Article of manufacture and method of making same



Oct. 3, 1939. H. c. FORREST 2,174,575

ARTICLE OF MANUFACTURE AND METHOD OF MAKljNG SAME Filed April 9, 1938 2 Sheets-Shed 1 INVENTOR ATTORN Oct. 3, 1939.

H. C. FORREST ARTICLE OF MANUFACTURE AND METHOD OF MAKING SAME Filed April 9, 1938 2 Sheets-Sheet 2 ATTO R N EY Patented Oct. 3,1939 2,174,576

UNITED STATES PATENT OFFICE ARTICLE OF MANUFACTURE AND METHOD OF MAKING SAME.

Henry G. Forrest, Merchantville, N. J.

Application April 9, 1938, Serial No. 201,063

3 Claims. (Cl. 18-54) This invention relates to a new article of manuunder the microscope from the generally circular facture, namely, a new artificial fibre which may cross-section of filaments of cupro-ammonium be spun into yarn by ordinary cotton spinning or silk yarn.

worsted and woolen spinning machinery, and to (5) Its cross-sectional shape Varies along its 5 a method of making the same. length. This feature is, so far as I am aware, 5

Rayon yarn is a slightly twisted thread comunique inarayon filament. posed of from 50 to 100 extruded regenerated cel- (6) It varies slightly and irregularly in denier lulose filaments. The individual fibres have along its length. This feature is readily observsmooth surfaces which give the yarn a shiny apable when it is examined under the microscope by 10 pearance resembling silk. The yarn itself and means of polarized light, for, with such light, 10 fabric woven from it, while having an appearance changes in color occur along the length of the resembling silk, have not the softness and pliabilfibre. This characteristic is not, so far as I am ity of a yarn spun from natural fibres or fabric aware, found in any other rayon filament. made therefrom. ('7) It is naturally and permanently curved or Attempts have been made to produce yarn by wavy. Its permanent waviness distinguishes it 15 spinning short or cut filaments of regenerated from other cupro-ammonium filaments, and the cellulose in the way in which cotton fibres are permanent character of this waviness distinspun, and it has been demonstrated that such guishes it from viscose filaments which have in yarn has not the harshness of rayon yarn. But some cases been given a temporary kinky form by the smoothness of extruded regenerated cellulose mechanical treatment. 2 filaments which, when out to short lengths, are (8) When made in small denier, it is readily known as rayon staple, has made it in most cases spinnable into yarn by ordinary cotton spinning diflicult to form them into yarn by cotton spinmachinery without previous mechanical treatning nery unless a considerable proportion ment and without admixture of any natural fibre.

5 of natural fibre is m xed with the The y Yarn spun from it by cotton spinning machinery spinnable rayon Staple Which has b Produced has the softness and pliability characteristic of has consisted of fine denier viscose filaments tt which have been mechanically treated by crimp- 9 w made in large deniera 11-, may b spun ing 01 in an'attempt to make them kinky into yarn by ordinary orsted and woolen pinand spinnable. Such staple has not been entirely Hing machinery The yarn spun from it has the 30 Satisfactory, particularly the lajrge 512%, m physical characteristics of worsted yarn and has Whlch thefilaments are and br 1tt1eproved an entirely satisfactory substitute for The artlfifnal fi Whlch I have mvented worsted and woolen yarns, and particularly for vides a read1ly spinnable rayon staple. The fibre the coarse woolen yams used in Carpet making has the following characteristics by Which it may and mohair goods. Such yarn forms the subject- 35 readfly be Identified and dlstmgmshed: matter of my application Serial No. 121,983, filed (1) It is a on ro-ammonium regenerated cel- Pm January 23, 1937, of which the present applicalulose filament of the same compositlon as the tion is a continuation in part filaments of cupro-ammonium artificial silk yarn.

In further explaining the characteristics of the (2) It is extlemely pliable so that, even when fibre which I have invented and the meth 1 40 2 r :g jg gg zii fif g i which I have invented for making it, I shall refer to the accompanying drawings:

characteristic, which is probably a result of the chemical composition of the fibre, distinguishes it Flgs- 1 to 4 are greatly rged Views of part from viscose filaments which lack pliability to P filajment P Y my such an extent that, when made of large size, they Flgi 1 1S a slfie View and Flgs- 2 to 4 are a genes are brittle and cannot be bent abruptly without of cross'sectlonscracking and breaking. Fig. 5 is a slightly enlarged side view of the (3) It has a rough and irregular surface by which it may readily be distinguished on micro- Figs- 6 d 7 are dlaglems lllustletlng a Specific scopic examination from the filaments of cupromethod 0f manufacturing he fi ment Shown in ammonium silk yarn which have smooth cylindri- Figs- 1 t0 5 With the use Of e pp tus Shownl cal surfaces. in my Patent No. 2,108,285, issued February 15, (4) It has an irregular non-circular cross-sec- 1938. F 6 s a diagrammatic S de elevation tion by which it may readily be distinguished with the front walls of the tanks and casings re- 55 moved and Fig. 7 is a plan view of part of the apparatus shown in Fig. 6.

Many of the characteristics of my new fibre which I have mentioned may be seen in Figs. 1 to 5. The rough surface of the fibre is evident in Fig. 1 which is drawn from an actual magnification of a 25 denier fibre embodying my invention taken at a magnification of 400 diameters. The irregular non-circular cross-section of the fibre and the variation in cross-section and denier along the length of the fibre are apparent from the cross-sectional views Figs. 2 to 4 which are taken from actual microphotographs of the fibre shown in Fig. l at the same magnification. The curve or wavy form of the fibre is apparent from Fig. 5 which is a slightly enlarged drawing from a 25 denier fibre embodying my invention. It will be understood that the portion of the fibre shown in Fig. 1 at a magnification of 400 diameters is too short to show the curvature of the fibre.

The specific method which I have found most successful and practical in manufacturing my new spinnable rayon staple consists in first making an untwisted rope or band containing a large number (for example 6000) cupro-ammonitun filaments by the method and apparatus described in my Patent No. 2,108,285, issued February 15, 1938. Such apparatus as there explained consists of a series of tanks, the first of which contains an extruding device or spinneret and the others of which have pairs of rollers with their axes set at angles to provide in each tank a continuously winding and unwinding fiat coil of the band or rope of filaments extruded in the first tank. Such apparatus is shown in the left-hand part of Fig. 6, wherein it will be seen that the first tank having the extruding device contains a caustic soda setting bath into which copper ammonium cellulose solution is extruded; and the next two tanks, 20 and 30, contain acid baths for removal of copper from the filament. This completes the chemical treatment used in the making of cupro-ammonium filaments. The next two tanks, 40 and 50, contain wash water, while the last tank, 60, contains a soap solution.

An important feature of the method consists in a slight controlled stretching of the filaments after the chemical treatment of the filaments is completed. This is accomplished in the apparatus illustrated by driving each successive pair of rollers slightly more rapidly than the preceding pair. Thus, the pairs of rollers may be driven by gearing (not shown) so that successive pairs are positively driven at the speeds indicated in Fig. 3, namely, R. P. M., 81 R. P. M., 82 R. P. M., 83 R. P. M., and 84 R. P. M. These figures are merely illustrative, and serve to show means for a gradual and controlled stretching of the chemically treated fibres amounting to about 5 per cent.

When the rope of filaments emerges for the last time from the tank 60, it is taken to a dry ing chamber 10 and formed into freely suspended loops, so that it is dried without tension and under conditions which permit shrinkage. The dried and shrunk filaments are then rewet with a hot soap solution or hot water either by immersion as indicated at 80 in Fig. 6, or by spraying the solution on the filaments, This causes the filaments to relax or elongate to the extent of about 2 per cent. The filaments are then again dried without tension, as indicated at in Fig. 6. During this drying, a further shrinkage takes place, reducing the filaments to about 90 per cent. of the length which they had on leaving the tank 60. The filaments are then out into lengths convenient for spinning. Lengths of from 1 to 2 inches are satisfactory for cotton spinning machinery, while lengths as great as 5 inches may be used in worsted and woolen spinning machinery. The cutting may be done after the second drying of the rope of filaments or at any time after the rope of filaments emerges from the tank 60, as the drying of the filaments without tension as well as the rewetting of the filaments by the hot soap solution or hot water may, if desired, be accomplished after the filaments have been cut.

The fibres produced by the method which has been described have the characteristics illustrated in Figs. 1 and 2 and described at the beginning of this specification.

While I do not wish to bind myself toany theory as to the operation of my method, a careful microphotographic examination of the new fibre indicates that, after the filaments are set and chemically treated, irregular strains are set up in the filaments, which, in the latter part of the process, are relaxed, so as to cause a permanent deformation of the filaments into the rough and regular form shown in Figs. 2 and 3. I believe that in the setting up of these irregular strains the slight twisting of the rope of filaments first in one direction and then in the other as it passes over the angled rollers may be an important factor.

What I claim is:

1. The method of making a spinnable rayon staple, which comprises extruding a cupro-ammonium cellulose solution into a precipitating bath to produce a wet cupro-ammonium regenerated cellulose filament, subjecting the filament to treatment with liquids while setting up irregular strains in the filament by stretching and then relaxing said strains to deform the filament and drying the filament in slack condition permitting free shrinkage to retain the deformation, and so feeding and guiding the filament during such treatment that it is free from folding.

2. The method of making a spinnable rayon staple, which comprises extruding a cupro-ammonium cellulose solution into a precipitating bath to produce a multiplicity of wet cupro-ammonium regenerated cellulose filaments, continuously feeding the filaments lengthwise, subjecting the filaments during such lengthwise movement to treatment with liquids while setting up irregular strains in them by subjecting them to a plurality of stages of stretching and between each two stages repeatedly slightly twisting and untwisting them, then relaxing said strains to deform the filaments by placing them in slack condition, and drying them in slack condition permitting free shrinkage to retain the deformation,

3. As a new article of manufacture, a spinnable rayon staple consisting of uniformly-extruded cupro-ammonium regenerated cellulose fibres of nmyuniform gross-sectional. shape and varying irregularly along their lengths in crosssectional area to an extent'sufficient to produce changes,inwcolorgmong their lengths when examined under the microscop by'means of polarized light and insufficient to be visible to the naked eye, and having as a result of such variations irregular surfaces and a naturally wavy form.

HENRY C. FORREST. 

